Method and apparatus for stretch forming elongated metal stock by wipe forming said stock lengthwise thereof



S. M. DOLNEY ETAL 2,810,421 METHOD AND APPARATUS FOR STRETCH FORMING. ELONGATED METAL STOCK BY WIPE FORMING SKID 'STOCK 'LENGTHWISE THEREOF Filed July 20. 1953 5 Sheets-Sheet 1 JNVENTOR.

ATTORNEYS 1957 s. M. DOLNEY ETAL 2,810,421

METHOD AND APPARATUS FOR'STRETCH FORMING ELONGATED METAL STOCK BY WIPE FORMING SAID STOCK LENGTHWISE THEREOF Filed July 20, 1953 I 5 Sheets-Sheet 2 ATTORNEYS.

Oct. 22, 1957 s. M. DOLNEY ETAL 2,810,421 METHOD AND APPARATUS FOR STRETCH FORMING ELONGATED METAL STOCK BY WIPE FORMING SAID STOCK LENGTHWISE THEREOF Filed July 20. 1953 5 Sheets-Sheet 3 T i TIME? ATTORNEYS Oct. 22, 1957 s. M. DOLNEY ETAL 2,810,421 METHOD AND APPARATUS FOR STRETCH FORMING ELONGATED METAL STOCK BY WIPE FORMING SAID STOCK LENG'H'IWISE THEREOF 5 Sheets-Sheet 4 Filed July 20. 1953 INVENTOR.

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93 ATTORNEYS.

Oct. .22, 1957 s. M. DOLNEY ETAL 2 ,810,421 METHOD AND APPARATUS FOR STRETCH FORMING ELONGATED METAL STOCK BY WIPE- FORMING SAID STOCK LENGTHWISE THEREOF Filld July 20, 1953 5 Sheets-Sheet 5 INVENTOR. 7

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51*. ATTORNEYS.

United States Patent.

METHOD AND APPARATUS FOR STRETCH FORM- ING ELONGATED IVIETAL STOCK BY WIPE FORIVHNG SAID STOCK LENGTHWISE THEREOF Stanley M. Dolney, Parma, and Henry W. Hein, North Olmstead, Ohio, assignors to The Cyril Bath Company, Cleveland, Ohio, a corporation of Ohio Application July 20, 1953, Serial No. 368,876

15 Claims. (Cl. 153-40) This invention relates to a metal forming method and apparatus and particularly to an improvement in a combined stretch forming and wipe forming apparatus of the general type disclosed in United States Letters Patent No. 2,514,830, issued July 11, 1950, to Cyril J. Bath, and to certain methods in the performance of which the improved apparatus is particularly useful.

There is disclosed in the above patent a metal forming apparatus for forming elongated strip stock, rods, tubes and the like and comprising a turntable rotatable about an upright axis and carrying a side face die about which a length of metal stock is to be formed. In forming the stock, one of its ends is anchored in fixed position relative to the die. The other end of the stock is clamped to a stretch forming head to which, by means of a fluid pressure operated cylinder and piston assemblage, yield able pressure is applied so as to exert an endwise pull on the stock. The yieldable pressure is maintained as the table is rotated so that the stock is stretched as it is Wrapped and formed about the die face.

In addition, a wipe forming shoe is provided and, by a fluid pressure piston and cylinder assemblage, is moved along a path of reciprocation extending generally laterally from the turntable into engagement with, and then maintained in yielding pressure contact with, the stock on the side face of the die so as to press the stock yieldably against the side face of the die substantially at the instantaneous point of tangency between the stock and the side face.

By means of these concurrently preformed stretch forming and wipe forming operations, very precisely shaped and dimensioned articles can be formed.

It is desirable that the direction of endwise travel of the curvilinear side face of the die at the instantaneous point of contact between the die and shoe be at all times as nearly as practicable at a right angle to the path of reciprocation of the wiping shoe during wipe forming so that the direct line of thrust of the yieldable wiping pressure applied by the piston and cylinder assemblage of the wiping shoe is as nearly as may be normal to a tangent to the side face through the instantaneous point of tangency. In such a relation only a relatively small component of force is applied by the die to the shoe in such a direction as to deflect the shoe transversely of its path of reciprocation.

In many cases, however, the side face of the die has portions so elongated and so eccentric to the axis of rotation of the turntable that, as the die is rotated so as to present its side face progressively from one end to the other against the wiping shoe, the direction of travel of the side face normal to its forming surface, as 'distinguished from its direction of endwise travel of its forming surface is at an abrupt angle, even 90", to the path of reciprocation of the Wiping shoe. In this relation an excessive component of force is applied by the die to the shoe transversely of the path of reciprocation of the wiping shoe and tends to deflect the shoe trans- 2 versely of its path of reciprocation. Quite often this angle is so great that substantially all of the force applied by the die to the shoe is that component force directed transversely of the path of reciprocation of the shoe. When this component becomes very large, the wiping shoe not only is subjected to severe stresses but a locking angle is reached wherein the angular relation of the force is one in which the die and shoe are pressed against each other under such high pressures that they frictionally interlock so that the die cannot be rotated, and the component of the applied force of the die against the shoe in the direction in which the shoe is moved by its yieldable pressure applying means is such a relatively small proportion of the total force applied by the die as to be ineffective to move the shoe along its path of reciprocation.

In accordance with the present invention, these objectionable effects can be overcome by mounting the wiping shoe so that the direct line of thrust of the force applied by its yieldable pressure means for moving it along its path of reciprocation toward and away from the side face of the die is more nearly at a right angle to a tangent to side face of the die at the instantaneous point of contact of the shoe and die throughout the forming operation, whereby the endwise travel of the side face of the die, as distinguished from its travel in a direction normal to the side face, is at an abrupt angle to its path of reciprocation of the shoe.

This is accomplished principally by mounting the shoe so that it can be moved, independently of the rotation of the table, to and fro to different positions along a traverse path extending in a direction generally lengthwise of the side face of the die or at a tangent to the side face of the die through the instantaneous point of contact of the shoe and side face and in all such positions along its traverse path can be reciprocated along its path of reciprocation toward and away from the side face of the die by its yieldable pressure applying means, and if desired, can be reciprocated along both of said paths independently or concurrently and regardless of whether or not the table is being rotated. More specifically, in accordance with the present in vention, the wiping shoe is mounted on a carriage means which supports the shoe for reciprocation along a path of reciprocation extending toward and away from the side face and for concurrent reaprocation generally endwise of the side face along a traverse path, the shoe carrying part of the carriage means being supported, in turn, for rocking movement transversely of the paths of reciprocation of the shoe about upright rocking axes, and respective power means,- iride pendent of each other of the power means for driving the table, are provided for yieldably pressing the shoe toward the side face of the die, for" causing the shoe to reciprocate along its traverse path, and for rocking the carriage means. V

The invention further resides in the combination of't'he wiping structure described with a stretch forming means and the method of combined wipe and stretch forming that can be practiced effectively with the combination with consequent improvementsin the grain str'uctur'e, surface finish and accuracy of the resulting article.

For purposes of illustration, the inventionwill bedescribed in connection with acombined Wipe forming and stretch forming apparatus in which the advantages of the invention are more fully developed, it being noted, however, that the apparatus described has some advan-, tages also in connection with apparatus adapted for wipe forming alone. i a

7 Various objects and advantages will become apparent frorr'rthe following description whefein reference is made to the drawings illustrating a preferred embodiment of the present invention, in which:

Figures 1 and 2 are a top plan view and a front elevation, respectively, of .a combined stretch forming and wipe forming machine embodying the principles of the present invention;

Figures 3 and 4 are an enlarged fragmentary top plan view and an enlarged fragmentary side elevation, respectively, of a portion of the machine illustrated in Figures 1 and 2, illustrating in greater detail the structure of the wipe forming shoe and its operating mechanisms.

Figure 5 is a right end elevation of the structure illustrated in Figures 3 and 4.

Figures 6 through 8 are diagrammatic illustrations showing the various manners of operating the wipe forming structure;

Figure 9 is a top plan view of a modified form of the combined stretch forming and wipe forming machine embodying the principles of the present invention; and

Figures 10 through 12 are an enlarged fragmentary top plan view, a front elevation, and a right end elevation, respectively, of a portion of the machine illustrated in Figure 9, illustrating different operating positions of the wipe forming shoe. 1

Referring first to Figures 1 through 5, the apparatus comprises a frame, indicated generally as 1, on which a turntable 2 is mounted for rotation about an upright axis, the turntable being driven by suitable power mechanism through a main driving gear 3 and a cooperable driven gear 4 as more fully set forth in the above identified Letters Patent.

The frame preferably has an elongated portion 5 which supports the stretch forming mechanism and a laterally extending portion 6, angularly disposed about the axis of the turntable from the portion 5, which supports the wipe forming mechanism. Mounted on the turntable is a side face forming die 7 which has an elongated forming face. A suitable anchor, as indicated at 8, is also provided on the die or on the turntable for anchoring one end of the length of stock S for rotation with the die. Mounted on the frame portion 5 is a stretch forming piston and cylinder assemblage, indicated generally at 9, including :a cylinder 10 and piston rod 11 reciprocable therein. The assemblage 9 is mounted on a platform 12 which, in turn, is mounted on the frame portion 5 for rotation about an upright pivot 13. Connected to the piston rod 11 for reciprocation thereby is a member 14 which carries stretch forming head 15 which is connected to the opposite end of the stock S. Yieldable pressure is applied by the assemblage 9 to the head 15 for exerting an endwise pull on the stock along a line from the axis of the pivot 13 to the instantaneous point of tangency of the stock with the side face of the die.

This structure and its operation are described in more detail in the above identified patent.

Mounted on the lateral frame portion 6 is a wipe forming piston and cylinder assemblage, indicated generally at 16, and including a cylinder 17 and piston rod 18 reciprocable therein. The frame portion 6 is provided with suitable guideways 19 extending parallel to the piston rod axis and in which a slide 20 is mounted for reciprocation parallel to the piston rod :axis. The slide 20 carries an upright pedestal or support 21 which, in turn, supports an elongated beam 22; The beam 22-is secured on the pedestal 21 by a suitable upright pivot 23 which supports the beam for rocking movement about the upright axis of the pivot 23. Mounted on the beam 22 is a reciprocating wiping shoe carrier 24 which is mounted on suitable longitudinal slideways 22a of the beam for reciprocation longitudinally thereof along a traverse path.

For reciprocating the carrier 24 to difierent positions along the length of beam 22, traversing power means are provided. In the form illustrated, the traversing power means comprises a power driven screw 25 drivingly connected to the carrier 24 by means of a suitable follower.

2,810,421 w a, p

. 4 The screw 25, in turn, is driven from both ends concurrently by electric motors 26 through the medium of speed reducing mechanism 27, either the motors 25 or the mechanism 27 being reversible. Preferably reversible motors are used so that they can be readily operated from a source by conventionalreversing switches.

A wiping shoe 28 of the type suitable for the particular operation is mounted on the carrier 24. Each motor 26 is supported on a support 26a which, in turn, is supported rigidly on the beam 22. Each mechanism 27 is supported by the housing of its associated motor 26. Since variations in the side face of the die may so require, the shoe 28 is mounted in the carrier 24 for quasi-universal movement; namely, for vertical lineal movement, rocking movement about a longitudinal axis parallel to the axis of the piston rod 18, as indicated at 28a in Figure 4, and rocking movement about a transverse horizontal axis 29a forwardly of the retaining pin 29 shown in Figure 5, which extends at to the longitudinal axis. Thus, the shoe can readily accommodate itself to the intricacies of the variations in the formation of the side face of the particular die.

To support the shoe for vertical movement, it is mounted on a support 28b which is vertically reciprocable in guideways 280 in the carrier 24. The shoe 28 has a supporting portion or element 28d having an arcuate forward face 28:: against which the face of the shoe opposite from the die engaging face is juxtaposed. The shoe 28 is held in engagement with the face 28a by means of pins 29 which are secured in the side portions 28g, respectively, of the portion 28d and engage arcuate slots 28h in the sides of the shoe 28, so that the shoe can rock about the common axis of the forward face 28a of the element 28d and the cooperating face of the shoe 28, which axis is forwardly of the pin 29, as indicated at 29a in Fig. 5. The element 28d is mounted pivotally in the support 28b, as indicated in Fig. 5, by a pin 281', for rotation about a horizontal axis which is parallel to the axis of the piston rod 18. The support 28b is reciprocable vertically by means of a piston and cylinder assemblage 28f.

'As hereinbefore set forth, it is desirable that the shoe be movable to different positions along a traverse path extending generally alongside the side face of the die independently of the rotation of the die and that it be rockable about an upright axis. For this purpose, in addition to mounting the shoe carrier 24 for movement endwise of the beam 22, the beam itself is rock-able about the upright axis of the pivot 23 by suitable auxiliary power means.

In the form illustrated, the auxiliary power means comprises a motor driven screw jack, indicated generally at 30 and connected at one end by a suitable arm 31 in fixed position relative to the pedestal or support 21. The jack includes a screw 32 having ball end 33 by which it is connected to the arm. The body 34 of the jack is connected to the beam 22 by means of a pivot 35. The jack includes the usual power driven follower which is driven by reversible electric motor 36 under the control of the machine operator. Thus by operating the motor 36 in opposite directions, the beam 22 can be rocked about the upright axis of the pivot 23. The slide 20, pedestal 21, beam 22 and shoe carrier 24 provide a carriage meanswhich supports the shoe for reciprocation toward and'away from the side face of the die and for reciprocation along an elongated traverse path extending generally endwise of the die face and arranged to be rocked transversely about an upright axis so as to direct the shoe along a path more nearly in parallelism withthe. side face of the die in various rotated positions of the die.

Referring next to Figures 6 through 8, there are illustrated diagrammatically a number of typical operating conditions encountered in the wipe forming of stock about elongated side face dies and the method by which the present apparatus solves the particular problem.

Referring to Figures 6 through 8, the table 2 is assumed to be rotating in a counterclockwise direction and the elongated side face die D is mounted in fixed position on the table in offset relation to the axis of rotation. One end of the stock S is anchored by the clamp 8 in fixed position relative to the die. The shoe 28 is yieldably urged toward the die and into contact with the side face by means of its piston and cylinder assemblage.

In the starting position illustrated in Figure 6, the beam 22 has been rotated slightly clockwise about its upright pivot. The shoe 28 can be reciprocated to and fro along the path generally parallel or tangent to a leading portion, indicated at a, of the die while yieldably pressed thereagainst. As the table continues to rotate and reaches the position illustrated in Figure 7, the beam 22 has been rocked in a counterclockwise direction about its point to a position generally parallel or tangent to the portion 12 of the side face. In this position the shoe is reciprocated back and forth to iron or Wipe form the piece against the side face. The line of thrust of the piston rod 18 is approximately normal to a tangent to the side face of the die through the instantaneous point of tangency between the die and shoe. It is apparent that upon continued rotation of the turntable, the right hand end of the portion 1) of the die would create a very large component of thrust to the left in Figure 7, horizontally and transversely of the line of thrust of the piston 18 or shoe 28 if the shoe could not be shifted along its traverse path. Accordingly, the side face die is maintained in the position illustrated in Figure 7 and the shoe 23 is reciprocated along the beam 22 for the full extent of the portion b of the die. This portion having been ironed out, the shoe is retained at about the right hand boundary of the portion b and the table rotated to bring the die in the position shown in Figure 8. Thereupon, the shoe can operate against the portion 0 without such great lateral components of thrust transversely of the path of reciprocation of the shoe 28 by the piston 17. In this latter operation the beam 22 is rocked through a considerable range so as to maintain the direction of thrust of the shoe as nearly as possible normal to the tangent at the instantaneous point of contact of the shoe 28 and die D.

When the trailing end portion 0 of the die approaches the shoe, the beam 22 is rocked further in a clockwise direction and thus, more generally into parallelism with the trailing end portion 0 of the side face. Thus the thrust of the piston rod 18 can be maintained at a very abrupt angle to the side face of the die.

Preferably, in all of these operations, the stock is maintained under tension by means of the piston and cylinder assemblage 9.

The table may be stopped, if desired, and the shoe 28 reciprocated along a portion of its traverse path which is adjusted substantially parallel to the side face of the die. Again, if desired, the wiping operation can be performed by applying the shoe against the stock and wiping unidirectionally from the starting end of the stock in a direction of pull of the stretch forming piston and cylinder assemblage 9 and, if additional wiping appears necessary, the shoe can then be released, returned to starting position and again wiped over the surface. On the other hand, if desired, the table may be permitted to rotate more slowly as the portion b of the die face is subjected to the shoe, and the shoe 28 operated by the traversing power means so as to pass over the portion b of the die rapidly while that portion is passing through a position approximately parallel with the beam 22. This wiping action also may be reciprocable movement or a unidirectional movement with the shoe moving in a direction of pull to which the stock is subjected by the stretch forming assemblage 9.

As mentioned, it is preferable to effect concurrent V 6 stretch forming and wipe forming of the stock though certain advantages are obtainable with merely wiping operation. If the wiping shoe is to be reciprocated along the stock instead of being moved unidirectiona'lly, it is essential that the stock be held under tension endwise.

Referring next to Figures 9 through 12, a modification of the apparatus is illustrated which comprises a frame 40,0n which a turntable 41 is mounted for rotation about an upright axis. A stretch forming piston and cylinder assemblage 42 is mounted 011 the frame for swinging movement about an upright axis and carries a stretch forming head 43 for connection to one end of the stock S. A suitable side face die D is carried on the table 41 and an anchor 44 is provided for an- IChOI'iDg the other end of the stock S for rotation with the die D.

In the prior structure, the piston rod of the piston and cylinder assembly for operating the wipe forming shoe toward and away from the side face of the die is mounted for movement along a path which is fixed relative to the frame and the traverse path provided by the beam 22 is rockable about an upright axis and relative to the line of thrust of the wipe forming piston and cylinder assemblage. The traverse of the shoe is due to movement of the shoe along the beam 22.

In the present form, however, the wipe forming shoe 45 is driven by a piston and cylinder assemblage 46 including a piston rod 47 connected to the shoe and a cylinder 48. The piston rod of the assemblage 46, instead of being mounted for movement along a path which is in fixed position relative to the frame of the machine, is mounted for movement along a path which is in fixed position on a platform 49. The platform 49 in turn is rockable about an upright axis on a carrier 50. The carriage 50 is mounted on a track 51 so that it can travel generally endwise of the side face of the die or the traverse path.

Power means for driving the carrier 50 along the track may comprise a reversible motor 52 which, by suitable belts, drives a feed screw 53 which is drivingly connected by the usual follower to the carrier 50.

The carriage 50 has a suitable arm 54 to which is connected a cylinder 55 of a reversible piston and cylinder assemblage. The piston rod 56 of the assemblage is connected to the platform 49 which is pivotally connected to the carrier 50 by means of a pivot 58. Thus, by operating the piston rod 56, the platform 49 can be swung to different positions about the axis of the pivot 58, thus changing the angle of reciprocation of the shoe toward and away from the side face of the die to effect in general the same results as are obtained in connection with the structure hereinbefore described. The end margin of the platform 49, at the end of the platform farthest from the pivot 58, fits into an arcuate guide 49a which is provided on the carrier 50. The range of swinging movement of the platform 49, and hence of the axis of the cylinder 48, about the pivot 58 is 15 counterclockwise, from normal position, in which the piston axis is at right angles to the traverse path, to 45 clockwise from the normal position.

A suitable pedestal 59 is provided and is rigid with the slide 57. The slide 57 is reciprocable in a path parallel to the axis of the cylinder 48. A shoe support 45a is mounted on the pedestal in the vertical guideway 60 for reciprocation vertically and is movable vertically by piston rod 61 by a reversible piston and cylinder assemblage 62. The shoe 45 is carried by the support 45a.

Throughout the specification and claims, the various parts of the apparatus have been described with relation to the vertical and horizontal but these terms are to be taken only in their relative sense for convenience in description. Obviously, the position of the parts relative to the horizontal and vertical is immaterial so long as the relation of the parts to each other is as described.

Likewise, for convenience in illustration, the present invention has been shown and described as embodied in the type of combined wipe and stretch forming machine disclosed in the aforementioned Bath Patent -No. 2,514,830, issued July 11, 1950, in which the die supporting table is mounted for rotation about its axis on a frame on which the wipe forming and stretch forming assemblages are also mounted, thus providing for movements of the stretch forming assemblage and wipe forming shoe assemblages, respectively, relative to the die, each in an arcuate path about an axis normal to the plane of the table.

In some prior stretch forming machines, like relative movement of the die and stretch forming assemblage is obtained by mounting the die on a supporting table which does not rotate about its axis, and mounting the stretch forming assemblage on a swinging arm which swings or rotates about the table axis.

Also, in some prior wipe forming machines, the die is mounted on a non-rotatable table and the wipe forming assemblage is mounted on an arm which swings about the table axis.

It is apparent that, in such prior structures, the movements of each assemblage relative to the die is controlling in operation. Thus, the relative movement may be maintained by actual rotation of the die supporting table, or by actual movement of the particular forming assemblage about the table, or both. The relative movement in each instance is in an arcuate path about an axis normal to the plane of the table.

Having thus described our invention, we claim:

l..A metal forming apparatus comprising a table, a side face die mounted on the table, a wipe forming shoe, means supporting the table and shoe for movement of said die and shoe in an arcuate path relative to each other about an axis normal to the plane of the table, power means to effect said relative movement, carriage means supporting the shoe for concurrent reciprocation toward and away from the side face of the die and generally endwise of the side face, primary power means operative to yieldably urge the shoe toward the side face, traversing power means operative to reciprocate the shoe generally endwise of the side face independently of said relative movement, means supporting a part of the carriage means to which the shoe is connected, for rocking movement about a second axis offset from, and parallel to, the first mentioned axis, and auxiliary power means operatively connected to the carriage means andoperable to rock the said part of the carriage means about the second axis.

2. A metal forming apparatus according to claim 1 characterized in that auxiliary power means are operable independently of the traversing power means.

3. A metal forming apparatus according to claim 1 characterized in that said carriage means includes a portion mounted for movement toward and away from the side face by the primary power means, and means connecting the shoe on said portion for movement of the shoe relative to the carriage means generally endwise of the side face, and the traversing power means are operable for reciprocating the shoe relative to said portion generally endwise of the side face.

4. The apparatus according to claim 1 characterized in that the carriage means has a base portion supported for movement generally endwise of the side face, and a rocking portion mounted on the base portion for rocking about said second axis, a slide is mounted on the rocking portion for movement relative thereto generally toward and away from the side face, and the shoe is carried on said slide.

5. The apparatus according to claim 4 characterized in that said primary power means are carried by the rocking portion and are connected to the slide.

6. An apparatus according to claim 1 characterized in that said carriage means has a base portion movable toward and away from said side face and yieldably urged toward'the side face by the primary power means and has arockable portion in the form of an elongatedbeam mounted on the base portion, means secured to said shoe are. secured on the beam for movement endwise thereof, and said auxiliary power means interconnect the base portion and rockable portion for rocking the rockable portion, and-the traversing power means are carried by said rockable portion and are operable to drive the shoe along the rockable portion.

7. A metal forming apparatus comprising a frame, a turntable mounted thereon for rotation about an up right axis, a side face die mounted on the turntable for rotation therewith, a stretch forming piston and cylinder assemblage mounted on the frame, an elongated carriage extending lengthwise generally alongside the side face of the die, a Wiping shoe movable lengthwise of the carriage, means supporting the carriage for bodily movement toward and away from the side face of the die, power means yieldably urging said carriage bodily toward the side face of the die, and power means to rock the carriage about an axis parallel to the axis of the turntable in any preselected rotated position of the die.

8. A metal forming apparatus comprising a table, a side face die mounted on the table, a Wipe forming shoe, carriage means supporting the shoe for concurrent reciprocation toward and away from the side face of the die and generally endwise of the side face, primary power means for yieldably urging the shoe toward the side face, traversing power mechanism for reciprocating the shoe generally endwise of the side face, stretch forming power means adapted for connection to a length of stock, and operable, when so connected, for applying yieldable tension on the stock endwise thereof for stretch forming the stock onto said die face in addition to any tensioning of the stock caused by the wipe forming operation, during wipe forming of the stock on the die by the shoe, and operable independently of the reciprocation of the shoe endwise of said face, means supporting the table, the stretch forming power means, and the carriage means, for relative movement of the die and stretch forming power means in an arcuate path, and relative movement of the die and carriage in an arcuate path, each path being about an axis normal to the plane of the table, and power means for effecting said relative movements.

9. A metal forming apparatus comprising a side face die mounted on the table, a Wipe forming shoe, carriage means for the shoe, said carriage means having a base portion supported for movement generally endwise of the side. face and having a rocking portion mounted on the base portion for rocking relative thereto about an upright axis, means on the rocking portion supporting the shoe for reciprocation relative to the rocking portion toward and away from the side face, primary power means carried on said rocking portion for yieldably urging said shoe toward the side face, traversing power means operatively connected to said base portion for reciprocating the base portion generally endwise of said side face, auxiliary power means operatively connected to said rocking portion and operable to rock said rocking portion about said upright axis, stretch forming power means adapted for connection to a length of stock, and operablewhen so connected, for applying yieldable tension to thestock endwise thereof for stretch forming the stock onto said face, in addition to any tensioning of the stock caused by the wipe forming operation, during wipe forming of the stock on the die by the shoe, and operable independently of the reciprocation of said base portion, means supporting the table, the stretch forming power means, and the carriage, for relative movement of the die and the stretch forming power means in an arcuate path, and relative movement of the die and the carriage in an arcuate path, each path being about an axis normal to the plane of the table and parallel to and offset from said upright axis, and power means to effect said independent relative movements.

10.. A metal forming apparatuscomprising a table, a

side face die mounted on the table, a wipe forming shoe, carriage means for the shoe, said carriage means having a base portion supported for movement generally endwise of the side face and having a rocking portion mounted on the base portion for rocking relative thereto about an upright axis ofiset from the die, means on the rocking portion supporting the shoe for reciprocation relative to the rocking portion toward and away from the side face,

primary power means carried on said rocking portion and operatively connected to the shoe for yieldably urging said shoe toward the side face, traversing power means operatively connected to said base portion for reciprocating the base portion generally endwise of said side face, auxiliary power means operatively connected to said rocking portion and operable to rock said rocking portion about said oflset upright axis, means supporting the shoe and die for movement relative to each other in an arcuate path about an axis normal to the plane of the table, power means for effecting said relative movement, and stretch forming power means adapted for connection to a length of stock, and operable, when so connected, for applying yieldable stretch forming tension to the stock endwise thereof, for stretch forming the stock onto said die face, in addition to the tensioning of the stock caused by the wipe forming operation, during wipe forming of the stock on the die by the shoe, and independently of the reciprocation of said base portion.

11. In the method of combined wipe and stretch forming elongated metal strip stock about a forming surface which is curvilinear endwise, in which method yieldable tension is applied to the stock from one end of, and endwise of, the stock so as to stretch the stock endwise as it is laid against the said surface progressively from one portion of the surface toward one end of the surface, the step of maintaining the tension while wipe forming the stock against the said surface progressively along the length of the stock in a direction toward said one end of the stock and in the opposite direction, successively, independently of the degree of tension maintained.

12. In the method of combined wipe and stretch forming elongated metal strip stock about a forming surface which is curvilinear endwise, in which method yieldable tension is applied to the stock from one end of, and endwise of, the stock so as to stretch the stock endwise as it is laid against said surface progressively from one portion of the surface toward one end of the surface, the step of maintaining the tension while wipe forming the stock against the said surface progressively along the length of the stock toward said one end of the stock at speeds different from the speed at which the stock is being laid on said surface, and independently of the degree of tension maintained.

13. A metal forming apparatus comprising a table. a side face die mounted on the table, a wipe forming shoe, carriage means for the shoe, said carriage means having a base portion supported for movement generally endwise of the side face and having a rocking portion mounted on the base portion for rocking relative thereto about an upright axis offset from the table, means on the rocking portion supporting the shoe for reciprocation relative to the rocking portion toward and away from the side face primary power means carried on said rocking portion and operatively connected to the shoe for yieldably urging said shoe toward the side face, traversing power means operatively connected to said base portion for reciprocating the base portion generally endwise of said side face, auxiliary power means operatively connected to said rocking portion and operable to rock said rocking portion about said ofiset upright axis, stretch forming power means adapted for connection to the stock, and operable, when so connected, for applying yieldable tension to the stock endwise thereof to stretch form the stock onto the die face in addition to any tensioning of the stock caused by the wipe forming operation, during wipe forming of the stock on the die by the shoe, and independently of the reciprocation of said base portion.

14. A metal forming apparatus comprising a table, a side face die mounted on the table, a wipe forming shoe, carriage means for the shoe, said carriage means having a base portion supported for movement generally endwise of the side face, means carried by the base portion and supporting the shoe for reciprocation relative to the base portion toward and away from the side face, primary power means carried on said base portion and operatively connected to the shoe for yieldably urging said shoe toward the side face, traversing power means operatively connected to said base portion for reciprocating the base portion generally endwise of the side face, stretch forming power means adapted for connection to the stock and operable, when so connected, for applying yieldable stretch forming tension to the stock endwise thereof to stretch form the stock onto said die face in addition to any tensioning of the stock caused by the wipe forming operation, during wipe forming of the stock on the die by the shoe, and independently of the reciprocation of said base portion.

15. A metal forming apparatus comprising a table, a side face die mounted thereon, a wipe forming shoe, a carriage means supporting the shoe for concurrent reciprocation toward and away from the side face of the die and generally endwise of said side face, primary power means for yieldably urging the shoe toward said side face, traversing power mechanism for reciprocating the shoe generally endwise of the side face for wiping a length of stock onto the side face of the die, stretch forming power means, means supporting the stretch forming power means and table for movement of the die and stretch forming power means relative to each other in an arcuate path about an axis normal to the plane of the table, said stretch forming power means being adapted for connection to the stock, and operable, when so connected, for stretch form- 1 ing the stock against the side face progressively from one portion of the stock toward at least one end of the stock at predetermined speeds by applying, during the wipe forming operation, yieldable stretch forming tension to the stock endwise of the stock, in addition to any tensioning of the stock caused by the wipe forming operation, said stretch forming power means being operable independently of the reciprocation of the shoe by the traversing power mechanism, and said traversing power mechanism being operable to cause the shoe to wipe the stock onto the side face at speeds different from, and also the same as, said predetermined speeds, selectively, and independently of the degree of tension being maintained by the stretch forming power means.

References Cited in the file of this patent UNITED STATES PATENTS 2,295,108 Hall Sept. 8, 1942 2,303,059 'Misfeldt Nov. 24, 1942 2,342,745 Maize Feb. 29, 1944 2,412,731 Hoffman Dec. 17, 1946 2,444,718 Bath July 6, 1948 2,514,830 Bath July 11, 1950 2,638,142 Green May 12, 1953 2,713,376 Bath July 19, 1955 

